1. Field of the Invention
This invention relates, in general, to an improvement in an internal combustion engine, and more particularly to a bearing cap installation arrangement of an automotive engine intended to effect engine noise reduction.
2. Description of the Prior Art
In connection with conventional automotive internal combustion engines, a crankshaft is rotatably supported by bearing caps which are secured to the bottom section of a cylinder block by means of cap bolts. The cap bolts are passed through the bearing caps and screwed in the cylinder block bottom section, and therefore the bolt head of each cap bolt is located on the bottom surface of the bearing cap. In this regard, the bearing cap is required to have shoulder portions serving as seats for the cap bolt heads. This considerably increases the weight of the bearing cap, thereby readily causing vibration of the bearing caps. The thus caused bearing cap vibration excites the vibration of a cylinder block skirt section connected to the bearing caps and of an oil pan, thereby emitting considerable noise.